com.yahoo.sketches.hive.frequencies.ItemsState Maven / Gradle / Ivy
/*
* Copyright 2016, Yahoo! Inc.
* Licensed under the terms of the Apache License 2.0. See LICENSE file at the project root for terms.
*/
package com.yahoo.sketches.hive.frequencies;
import org.apache.hadoop.hive.ql.udf.generic.GenericUDAFEvaluator.AbstractAggregationBuffer;
import com.yahoo.memory.Memory;
import com.yahoo.sketches.ArrayOfItemsSerDe;
import com.yahoo.sketches.frequencies.ItemsSketch;
class ItemsState extends AbstractAggregationBuffer {
private int maxMapSize_;
private final ArrayOfItemsSerDe serDe_;
private ItemsSketch sketch;
ItemsState(final ArrayOfItemsSerDe serDe) {
serDe_ = serDe;
}
// initializing maxMapSize is needed for building sketches using update(value)
// not needed for merging sketches using update(sketch)
void init(final int maxMapSize) {
maxMapSize_ = maxMapSize;
sketch = new ItemsSketch(maxMapSize_);
}
boolean isInitialized() {
return sketch != null;
}
void update(final T value) {
sketch.update(value);
}
void update(final byte[] serializedSketch) {
final ItemsSketch incomingSketch = ItemsSketch.getInstance(Memory.wrap(serializedSketch), serDe_);
if (sketch == null) {
sketch = incomingSketch;
} else {
sketch.merge(incomingSketch);
}
}
public ItemsSketch getResult() {
return sketch;
}
void reset() {
sketch = null;
}
}